Maybe he'd like to get to know you better, but he's shy and unsure what to say in an actual message. Or, he might be the kind of guy who winks at a lot of woman and can't be bothered sending a message. If this is the case, it doesn't mean much.
The law of conservation of mass (from Lavoisier) states that mass can be neither created nor destroyed (but it may change its form into something that is not desired, such as heat with an engine) or that in a chemical reaction, the total mass of the reacting substances is equal to the total mass of products formed.
For sustainable energy resources, see Energy conservation. In physics, the law of conservation of energy states that the total energy of an isolated system remains constantâit is said to be conserved over time. Energy can neither be created nor destroyed; rather, it transforms from one form to another. For instance, chemical energy can be converted to kinetic energy in the explosion of a stick of dynamite. A consequence of the law of conservation of energy is that a perpetual motion machine of the first kind cannot exist.